Authentication protocols of communication systems typically rely on key information stored in a security module, such as a SIM (subscriber identity module) card, in the mobile station, and in a specific network node such as an AuC (authentication center) node. The key information can be a shared secret, or for example a private/public key pair. In systems where a shared secret is used, authentication information is produced on the basis of the shared secret, and typically used in a challenge-response protocol to authenticate the mobile station to the network.
The continuing development of cellular telecommunication systems brings about developments in the authentication procedures used between a mobile station and the network. This inevitably results in interoperation problems with a widely used base of older equipment and new systems.
The generic authentication architecture (GAA) is under standardization for 3GPP (third generation partnership project) system release 6 at the time of writing of this patent application. The 3GPP standards specify certain authentication procedures which require certain capabilities of the security module of a mobile station. However, there is a wide installed base of GSM (global system for mobile communications) technology with large numbers of subscribers, resulting in the problem of how to use older GSM SIM cards in conjunction with the newest authentication procedures, as the SIM cards are unable to provide key material as required by these newest authentication procedures. The inventor envisions that similar problems may arise also later, when a further generation of technology is developed to replace the third generation (3 G) technology currently in development.